We present results of pulsation analyses of B-type supergiant models with masses of 14 - 18 M _ { \odot } , considering evolutionary stages before and after helium core ignition .
Using a non-adiabatic pulsation code , we compute instability domains for low degree modes .
For selected models in these two evolutionary phases , we compare properties of pulsation modes .
Significant differences are found in oscillation spectra and the kinetic energy density of pulsation modes .